Abstract: A need exists for representation of the interlock strength of steel sheet piling as a distribution for two main reasons. First, this strength is highly variable, and second, this aspect of design of a sheet pile system depends on the strength of the weakest interlock. In this investigation a total of 220 interlock tension tests were run on PS28 steel sheet piling from two different sources. From these tests frequency distribution diagrams were developed. A considerable difference in the results demonstrated a sensitivity of one of the two products to initial alignment. The study of the failure mechanism further suggested that relative alignment angle of adjacent webs, not considered in this program, may have a considerable influence on interlock strength. Consequently, while this study provides for an improved concept of representation of interlock strength it demonstrates a possible need for improved testing techniques.